This is a good idea to think to save the state of your workspace time to time.
Click on add data
Search for SRTM elevation, click on the SRTM 30m digital elevation Data product
Click on the question mark icon to get further information on the selected product.
Click on add computation
Select Slope and aspect. Then select the elevation maps as reference. By default the visualization will be based on a combination both elevation and aspect (RGB).
To make it simpler we will here just focus only on the slope band.
Click on the Slope and aspect product on the left panel, select the Slope band, and setup the color scale to cover 100% of the slope range (0-90).
Here we are on a grey-scale. We can choose to define our own color-scale. You can for instance use the excellent website http://colorbrewer2.org/ to generate a html color-scale that suits you.
I choose here this color-scale:
ffffcc,ffeda0,fed976,feb24c,fd8d3c,fc4e2a,e31a1c,bd0026,800026
You can easily set it clicking on Palete then on the pen icon and pasting your colors scale in hexadecimal format.
You should now have something like:
Click on the slope map feature in the left panel, then click on the downloading arrow. Select the area, projection system and resolution that suits you and click on Download.
A window will pop-up..
Click ok … You are done !!!
Note: In case you didn’t manage to make it or if you want to compare you results to mine you can use one of the following sections.
Here is the link to the final workspace
Here is the Json version of the final workspace. You can copy this lines and import them in your workspace.
{
"viewport": {
"zoom": 10,
"lat": 45.22267719962014,
"lng": 5.9161376953125
},
"name": "",
"classmodel": [],
"polylayers": [],
"datalayers": [
{
"title": "Computed layer: Slope And Aspect",
"originaltitle": null,
"overlayvisible": true,
"vis": {
"opacity": 0.51,
"bands": [
"slope"
],
"max": 44,
"palette": [
"ffffcc",
"ffeda0",
"fed976",
"feb24c",
"fd8d3c",
"fc4e2a",
"e31a1c",
"bd0026",
"800026"
],
"format": "png"
},
"layermode": "advisory-mode",
"datatype": "computed",
"computations": [
{
"title": "1. Slope And Aspect",
"operation": "TerrainSlopeAspect",
"layer": {
"image": {
"type": "Invocation",
"arguments": {
"id": "USGS/SRTMGL1_003"
},
"functionName": "Image.load"
},
"bands": [
"elevation"
],
"title": "SRTM Digital Elevation Data 30m"
}
}
]
},
{
"title": "SRTM Digital Elevation Data 30m",
"originaltitle": null,
"overlayvisible": false,
"vis": {
"opacity": 1,
"bands": [
"elevation"
],
"min": 0,
"max": 6000,
"gamma": 1.6
},
"layermode": "advisory-mode",
"datatype": "image",
"assetid": "USGS/SRTMGL1_003"
}
],
"drawnpoints": [],
"drawnpolys": [],
"analysis": null
}